1. Technical Field
The present disclosure relates to a light-emitting device and the manufacturing method thereof.
2. Description of the Related Art
Light-emitting diode (LED) possesses the intrinsic characteristics of rectifying current and emitting light. When LED is forward biased, the current is dramatically rising in a forward direction as the driving voltage crossing the LED is gradually increased and therefore light is emitted with a corresponding wavelength. The driving voltage at which the current starts to be rapidly rising is normally called forward voltage (Vf). Contrarily, when the LED is reverse-biased, the driving voltage crossing the LED has to reach a critical value so that the current is noticeably rising. The reverse-biased driving voltage at which the current starts to be noticeably rising is normally called reverse voltage (Vr).
The ordinary Vr value of gallium nitride (GaN) based LED is usually around −15˜−20 volts. The poor Vr performance is normally caused by defects existed in the epitaxy thin film, such as lattice dislocation, impurities, and other parasitical leakage path so the device is not able to resist strict reverse-bias condition. Therefore the LED fails or breaks down easily during operation.